Encyclopedia of Veterinary Terms

abacterial

abattoir

abaxial

Abaxial is a term that refers to something in particular being found away from the center of the body or the body part in question.

abdomen

The abdomen is the part of the body between the chest and the hips. It contains some of the most vital organs of them all, including the stomach and intestines, the bladder, the liver, and other vital organs. Abdominal is an adjective term that refers to something pertaining to the abdomen.

abdominal breathing

Abdominal breathing is an irregular type of breathing that uses the muscles in the wall of the abdomen to move air into the lungs and pump it back out. Abdominal breathing is not normal and is normally the indicator of some type of respiratory condition or infection.

abdominal cavity

The space in the abdomen that holds the major digestive organs in an animal. Normally referred to as the area between the diaphragm and the pelvis. Also referred to as the peritoneal cavity.

abdominal effusion

Refers to a condition in which fluid collects around the vital organs located inside the abdomen. This is normally the side effect of a more serious condition, like liver disease or heart disease. Certain bacterial infections can also cause the build-up of such fluid, as can certain types of cancer. An animal experiencing abdominal effusion will likely have an extremely bloated midsection.

abdominal wall

The abdominal wall is a group of bones, muscles, and vital tissues that make up the wall around the organs in the abdomen. Inside these bones, muscles, and tissues is a cavity, and the cavity is what houses the vital organs found inside the abdomen. The abdominal wall is vital for protection of these organs.

abdominocentesis

Abdominocentesis is a procedure in which a needle is inserted into the abdomen of the animal to remove fluid. In most cases, abdominocentesis is used to make a diagnosis of some sort in a sick animal.

abduct

Abduct is the opposite of adduct. It refers to the movement of something away from the animal's midsection.

abiotrophy (n.)

Abiotrophy refers to the loss of use of an organ in particular. In most cases, this is a progressive condition and is inheritable. Abiotrophy may occur in an organ, a tissue, or even the nervous system.

ablactate

To take off of the teat or to stop from nursing; to wean an animal off of its mother's milk.

ablate

To ablate is to complete take something out of something else. Ablation (n.) refers to removal of a particular body part by cutting it out.

abomasopexy

The surgical procedure of attaching the fourth stomach (the abomasums) compartment to the abdominal wall.

abomasums

In animals, the fourth of several stomach compartments. Also referred to as the true or real stomach.

aboral

Used to describe a direction; away from or outside an animal's mouth.

abort

To end the pregnancy early; in animals, usually used to describe similar circumstances as a ‘miscarriage' in humans. An abortion (n.) is used to describe the ending of a pregnancy whether purposeful or accidental.

abortive

Fails to work properly; unfruitful. In veterinary medicine, used to describe an animal that is barren or unable to successfully reproduce.

abrasion

An injury that has occurred in which one or more of the topmost layers of the skin are scraped away. Also known as a scrape.

abscess

A localized infection, usually a lesion filled with pus. Can be large or small in size.

absolute age

In veterinary medicine, refers to an animal's actual age in calendar years rather than the age pertaining to their development. ex: absolute age (actual age) vs. age in ‘dog years.

absorption

In veterinary medicine, the joining of already digested nutrients with the circulatory system. Absorption is how an animal's body makes use of nutrients from food.

absorption rate

The rate at which digested nutrients enters the circulatory system.

abundance

The number of animals per unit area. ex: five horses per square acre.

acariasis

Refers to the condition of being overrun with parasites, such as ticks or mites.

acaricide

Any substance known to kill certain parasites, including ticks and mites. May be found in the form of a paste, a liquid, or a powder.

acarid

Refers to any tick or mite belonging to the order Acarina or the family Acaridae.

acarine

A mite or a tick.

acclimate

To become accustomed to new actions, surroundings, environment, or companions. Ex: a dog may need to acclimate himself to a new home upon adoption from a shelter.

acclimatization

The act of helping an animal to adjust to something or some place foreign to them.

accommodation

A process, that of adjusting the eye to see objects at a variety of distances.

accredited herd

Accredited herd is a term that is used to refer to dairy cattle that has been tested and received the certification necessary to be declared free of tuberculosis as described by the United States Department of Agriculture. To be considered part of the accredited herd, two tests given must be passed.

accuracy of selection

Accuracy of selection refers to the difference between what an animal's breeding value was estimated to be and its actual breeding value.

acetabulum

The socket that holds the head of the femur, found in the pelvis of a given animal.

acetic acid

Chemically described as CH3COOH. In the veterinary context, acetic acid is used in the fermentation of lactic acid and a necessary component of taste in certain dairy products.

acetic bacteria

The bacteria that is involved with turning alcohol into acetic acid.

acetic fermentation

Acetic fermentation is the process of turning ethyl alcohol into acetic acid with the use of fermenting bacteria.

acetone

Chemically described as CH3COCH3, created from the fermentation of sugar and starch. Acetone can be found in the urine of a diabetic animal, the breath of certain lactating animals, and in blood. When found in lactating animals, acetone indicates a deficiency, usually of carbohydrates resulting from an inability to properly oxidize fat in feed.

acetonemia

Acetonemia is a disease. It involves the presence of large amounts of acetone in the blood. This condition is also referred to as: milk fever, acidosis, acetenouria, pregnancy disease (in ewes).

achalasia

Refers to difficulty or lack of ability to release the smooth muscle in the digestive system, found in the gastrointestinal tract.

achondroplasia

Refers to the changes undergone by the skeletal system during development of the fetus; has the ability to be inherited genetically.

acid

Any substance or solution with a total pH of less than 7; a term used to described low pH or an increase in the number of hydrogen ions in a given substance.

acid-fast

Resists the effects of acids; has less of a chance of losing color due to acidic properties

acidified silage

Refers to silage that is preserved with the help of certain types of acid, including sulfuric or hydrochloric acid, some combination of sulfuric and hydrochloric acid, or commercial phosphoric acid.

acidity

Refers to the density of hydrogen ions in a given solution.

acidophilus

A term used to describe an organism that tends to thrive in an acidic environment, such as soil rich in acid.

acidosis

A condition of the body in which pH levels are abnormally low.

acoustic

Refers to the sound properties of a given item.

acquired character

The changes that the character of a particular animal has gone through, whether the be physiological or otherwise. May be due to the environment that they live in. Acquired character cannot be passed on and it is not genetic in nature.

acquired immunity

Refers to the immunity that can be built up to a disease or illness that an animal would normally fall victim to. There are several reasons why this is, and it may be an active immunity (antibodies build up through having the disease) or passive immunity (e.g., immunity passed on through mother's milk or an animal's serum).

acre per animal unit month

A measurement; used to figure the number of acres that are needed for one animal to be able to forage easily for one month when used properly.

acromegaly

An issue caused by excessive growth hormones in which the extremities become larger in size.

acromion

The outer edge of the scapula; this is where the collar bone is attached to the animal's body.

acrosome

Refers to the small cap that covers the head of sperm.

active agent

Also referred to as active ingredient; a term used to describe the ingredient in a chemical that poses a toxic threat to a particular animal.

active immunity

Refers to immunity that is built up through exposure to the disease or pathogen.

actual analysis

The compiling of materials using a chemical analysis generated in a laboratory rather than a generalized analysis.

actual use

Term used to refer to the amount of area used by certain animals, e.g. livestock or hunting game; expressed in animal units or animal unit months.

acuity

The property of being sharp; in veterinary medicine, usually refers to the quality of an animal's vision.

acute

Term used to imply that a situation or condition is more severe than usual; also used to refer to a disease having run a short course or come on suddenly.

acute renal failure (arf)

The failure of the kidneys; loss of function of the kidneys. ARF usually comes on suddenly.

acute toxicity

The potential that something, usually a medicine or substance, has to injure or cause illness in an animal when given as one dose or as multiple doses in the span of one day or less than one day.

ad lib

As much as needed or wanted; short form of the word ad libitum

ad lib feeding

Term used to refer to a type of feeding in which there are no restrictions placed on the amount of food to be given at any time.

ad libitum

Often shortened to ad lib; term used to refer to the amount of feed ingested when made completely available without limitation or restriction.

adaptability

The potential that an animal or organism has to change their bodies or lifestyles to suit their surroundings or environment.

adaptation

Term used to refer to the activities or processes that an animal goes to make changes necessary for it to survive in its current environment, whether temporarily or otherwise.

additives (n.)

Items or ingredients added to feed as part of the manufacturing process; may also be used for preservation. Additives also work to increase nutritional value of certain foods, increase the taste appeal, and make it more attractive. There are legalities surrounding the amounts and types of additives allowed in feed.

addled egg

The result of the mixing of an egg's yolk with the egg white. May also be referred to as a rotten egg, and cannot be eaten.

adduction

To move inward or toward the midsection of the animal.

adenocarcinoma

The result of a malignant growth of the tissue of the epithelial gland.

adenohypophysis

The rearmost pituitary gland; the only area of the pituitary gland that is functional.

adherence

A property in which one item has the ability to stick or adhere to another.

adhesion

Fibers that bond items together that would not normally be combined.

adipocyte

A cell of fat

adipose

Refers to the quality of being fat or full of fat.

adjusted weaning weight (adjusted 205-day weight)

The weight of a young animal at the time of weaning; this weight is adjusted to the standard for 205 days old as well as the age of the dam itself.

adjusted yearling weight (adjusted 365-day weight)

The weight of a yearling after adjustments for the age of the dam and adjusted to a standard 365 days old. b) changes in the numbers of animals, the seasons, classes or types of animals.

adnexa

The structures of any given organ.

adrenal cortex

The outermost part of the adrenal gland

adrenal gland

The gland that produces the hormone adrenaline and others; helps to regulate the metabolism, electrolytes, and even sexual function; also helps to regulate the way the body responds to injury, trauma, etc. The adrenal gland is found near the kidney. Also referred to as the suprarenal gland.

adrenal medulla

The innermost part of the adrenal gland.

adrenalectomy

The process of surgically extracting one or both of the adrenal glands.

adrenaline

A hormone produced by the adrenal glands, also often referred to as epinephrine. Adrenaline is used in the body's response to traumatic situations or emergencies.

adrenopathy

Term used to refer to a type of disease that affects any portion of the adrenal glands.

adventitious sounds

Sounds of the respiratory system; e.g. bronchi, rales

aerobe

Term used to refer to certain types of bacteria or organisms that only have the ability to survive in an environment of free oxygen.

aerogun

Term used to refer to bacteria with the ability to produce certain types of gas.

aerophobia

The act of swallowing air.

afebrile

A state, usually of illness, in which the subject is free of fever.

afferent

Carrying toward; usually refers to nerves in the nervous system that carry certain impulses.

aflatoxin

A substance created by a certain fungus, Aspergillus flavus, a carcinogen; known to contaminate corn, some nuts, and certain types of grain.

afterbirth

Found attached to the fetus while en utero; expelled upon birth of the fetus. Term used to refer to the placenta.

agalactia

A condition in which an animal fails to nurse after birth of the offspring due to lack of secretion of milk; condition often found in female horses.

agalactic mare

A female horse that is not properly lactating to feed her foal.

age class

Term used to describe the grouping of animals by age.

aged horse

Term used to describe a horse over the age of eight years old; often used to refer to a horse over the age of 12 years old.

agglutination

The grouping together of certain cells, molecules, or particles into one area or clump.

agglutinins

a) antibodies that are created as an animal's natural response to an infection or the presence of strange micro organisms; these antibodies cause the organisms to clump together. b) any substance or antibody that causes certain organisms to clump together; usually causes the clumping of the organism that caused it to be produced in the first place.

agonal breathing

The breathing that occurs when an animal is near death or suffering from severe pain.

agonist

Any substance that causes a certain effect by attaching itself to the right receptor.

agonistic

agoraphobia

The term for a fear of wide open spaces; in veterinary terms, refers to animals who are kept stabled or in stalls for an extended period of time.

agostadero

Term used mostly in the southwestern United States; refers to a pasture that is used only during the summer months.

agouti

A type of coat pattern in which the fur is darker toward the root and becomes gradually lighter near the tip.

agranulocyte

Any cell that does not have the normal granular structures in the cytoplasm.

agrarian

Anything pertaining to or relating to the agriculture industry.

agriculture

A broad term used to indicate the industry involved with producing animals and plants for use by humans.

aids

Used in the equine industry; indicates the methods by with a rider communicates with his horse.

air sacs

An avian term; refers to pockets in the respiratory system of birds that hold air and allow them the ability to fly and the buoyancy necessary to do so.

albidus

Term that indicates something being white in color.

albino

An animal who lacks normal coloring; lack of melanin. Albino animals usually have a pure white coat and pink or red eyes.

albumin

A type of protein that can be dissolved in water; found in milk, egg white, certain muscle, blood, and some urine.

albuminaria

A condition in which albumin is found in urine.

albus

A term indicating that something is white in color. See albidus.

alcohol

The term used to refer to a family of organic chemical compounds that consist of carbon, hydrogen and oxygen in any form.

alcohol test

A test performed in which milk and ethyl alcohol are combined to detect milk with abnormal properties. While normal milk should not cling to the tube, abnormal milk tends to cling to the glass.

alcohol-alizarin test

A test performed in which alcohol and alizarin are combined with milk. If the solution turns reddish, that indicates the presence of normal milk. If the solution turns yellowish or brown in color, that is the indication of sour or rotten milk. A solution that turns purple or violent in color indicates the presence of mastitis milk.

aleukia

A condition in which leukocytes (white blood cells) are not found in the blood of an animal.

alfalfa

A crop; often eaten by horses as a vital source of fiber and protein. Alfalfa has compound leaves made up of three small leaves.

alimentary tract

Term refers to the system in the body that deals with the processing of food and nutrients in between the mouth and the anus; may also be referred to as the GI tract, the intestinal tract, or the gastrointestinal tract.

alkaline

A property of having a high pH or a low amount of hydrogen ions.

allantois

The layer of the placenta closest to the inside.

allergen

Any substance with the potential to produce an allergic reaction in an animal prone to such a reaction.

allergy

A condition in which the body reacts to a particular item or product; may also be referred to as hypersensitivity.

allogamy

The process of cross-fertilization.

allopolyploid

Term used to refer to a polyploidy that contains chromosomes that are different from one another, as in from more than two species.

allosomes

Term used to refer to a type of chromosome that is different in one reason or another, either by a discrepancy in behavior, shape, or size.

allotment

In the agricultural industry, term used to refer to an area that is designated for use by a certain number of cows or sheep or for use by both types of animals.

alopecia

A condition of hair loss resulting in either complete baldness or patches of baldness.

alpaca

a) a type of llama found in Peru and adjacent South American countries b) the product of the alpaca; a type of wool that can be used to create goods.

alter

To change by neutering or spaying. May also be referred to as cutting, gelding, or emasculating.

alteration of generations

A theory of reproduction in which certain characteristics are only found in every other generation.

alternate grazing

The process of rotating pastures in a manner which allows the forage to grow back before it is grazed once more. May also be referred to as rotational grazing.

alternate host

An organism in which a parasite or organism inhabits for only a certain part of its life cycle.

amasesis

A term used to refer to an animal without the ability to chew.

ambidextrous

Refers to a living thing that can use both hands equally well, as in not solely considered to be right-handed or left-handed.

ambient

Around or surrounding.

amble

A type of gait that is slower or broken up in cadence; usually lateral.

ambler

Term used to refer to a type of horse who paces; usually refers to sporting horses.

amblotic

Term used to refer to a substance, organism, or disease that has the potential to cause abortion in animals.

amblyopia

A condition in which loss of sight occurs without being attributed to any particular disease or medical condition.

amino acids

Organic substances that aid in the creation of proteins; also the end product of the decomposition of certain proteins.

amitosis

A condition of the body that occurs when an excess amount of amino acids is taken in.

ammonia

A chemical compound made of nitrogen and hydrogen; NH3. Often added to feed to make it more nutritious for livestock; usually lacks color but has a strong odor.

amnesia

A condition in which loss of memory occurs.

amniocentesis

The process of obtaining abdominal fluid by puncturing the abdomen with a needle and going through the walls of the uterus to obtain it.

amnion

The membrane in the uterus that is closest to the fetus; also referred to as the amniotic sac.

amniotic cavity

Term refers to the area in the uterus that surrounds the embryo.

amniotic fluid

The fluid that nourishes the fetus; found in the amniotic sac.

amoeba

An organism with no shape or form; moves with the help of a false foot.

amotus

A term that refers to the hind toe in certain species of birds; the amotus is not one of the digits that touches the ground when the bird is standing.

amphibian

A term used to refer to an animal, usually a reptile, that starts out breathing with the help of gills and develops into an animal capable of breathing through lungs like a mammal.

amphigean

A term used to refer to an animal that exists in both the Old World and the New World.

amphoteric

The property of having the ability to react as an acid, base, or casein.

ampule

A term used to describe a measurement unit for packaging.

amputation

The process of removing all or part of a body part; usually refers to a limb (arm or leg) and is done for medical reasons.

amylase

Term used to refer to a certain enzyme that the pancreas creates to help in the digestion of certain starches.

amylopsin

An enzyme created by the pancreas to break sugars down into starch.

anabiosis

The act of reviving a living thing after it has died or appeared to have died.

anabolism

Building up or building together; the building of cells in the body. The term opposite to catabolism.

anadipsia

A condition referring to excessive thirst.

anaerobe

Term used to refer to an organism that can live without the aid of free oxygen; usually refers to certain types of bacteria.

anaerobic

a) living in an environment lacking free oxygen b) pertaining to an organism with the ability to live in an environment lacking free oxygen.

anaerobic bacteria

Bacteria that does not require the presence of free oxygen to live, survive, and reproduce; may even be hindered by the presence of free oxygen in their environment.

anal

Term used to refer to something involving the last portion of the digestive process and the last abdominal segment, the anus.

anal glands

Tissue located inside the anal sac that aids in the marking of territory in animals, for defense, or for sexual behavior.

anal sacculitis

A condition inw which the pouches inside the anus become inflamed.

analgesia

Without the presence of pain.

analgesic

Any medication that is designed to aid in relieving pain without being a sedative.

analogous

In veterinary medicine, term used to refer to structures that are anatomically different but perform functions that are somewhat the same in nature.

anaphylaxis

Term used to refer to an animal's response to a certain substance, usually foreign; may include swelling, airway blockage, etc; may also be referred to as anaphylactic shock.

anaplasia

Any change in the way that cells are arranged and structured in relation to one another.

anastomosis

A surgical procedure in which two hollow tubes or structures are surgically connected.

anatomic position

Term used to refer to an animal in its regular standing position.

anatomy

The study of the structure of the body.

ancestor

Any individual from which a person or animal is descended.

ancestor merit

Used in agriculture; a term used to refer to the estimate of the female offspring of any given bill based on the bull's sire and grandsire on its maternal side.

androgenesis

The theory of the development of any offspring that lacks maternal chromosomes.

androgynized cow

Term used to refer to a cow that has undergone testosterone therapy; usually adorned with a bell-shaped marker.

anechoic

A term used to refer to an ultrasonic wave that is transmitted into tissue without it being reflected back.

anemia

A condition of the blood in which normal red blood cell counts or hemoglobin are lacking.

anesthesia

The absence of feeling; a medication administered to relieve the sensation of feeling in surgery or other medical procedures.

anesthetic

Any substance known to eliminate feeling; usually applied during a painful medical procedure.

anestrous

The period in which an animal is not inclined to mate or breed; any time in which a female animal does not cycle.

aneurysm

The enlargement of an artery; usually shaped like a bubble or balloon.

angiocardogram

A study of the vessels and heart by way of radiograph; uses dyes and other contrasting materials.

angiogram

The study of blood vessels after dye has been injected into them to create a visual contrast.

angiopathy

A disease of the blood vessels.

angioplasty

The process of surgically fixing or repairing damaged blood vessels.

angiorrhaphy

The suturing of a blood vessel.

angora

Term used to refer to longer fur, usually found on cats or rabbits.

anhydrosis

Term used to refer to a state in an animal in which it cannot sweat.

animal kingdom

The entire group of animals in the world; consists of twelve branches of animals.

animal rights

The term used to refer to the idea that animals are entitled to similar rights as human beings and should not be eaten or abused. Also known as animal welfa

animal therapy

The use of animals as therapy for human beings; may be used to relieve loneliness or provide comfort and soothing.

animal type

Any combination of qualities or characteristics in an animal that makes it appropriate for a certain kind of use.

animal welfare

Similar to animal rights; the idea that animals should be treated with care and kindness.

anisocoria

A medical condition in which the pupils of both eyes are differently sized.

anisocytosis

A condition in which cells are unequal.

ankylosis

A condition in which a joint is unable to move, usually due to some type of illness or medical procedure.

anogenital distance

The distance between the anus and the reproductive organs

anomaly

Anything deviating from what is usually regarded to be normal.

anophthalmos

Lacking the development of one or two eyes.

anoplasty

A surgical procedure in which the anus is repaired.

anorectal

Term used to refer to the opening of the large intestine.

anorexia

In veterinary terms, used to refer to the loss of appetite or lack of eating.

anoxia

Refers to the lack of oxygen.

antagonism

Term used to refer to what happens when chemical is exposed to another chemical.

antagonist

Term used to refer to any substance that is used to stop something from happening by binding to a particular receptor that is responsible for that

antebrachium

The area of the front legs that is found between the elbow and the carpal joints.

antefebrile

Term used to refer to the time before a fever sets in.

antepartumtion of the body

Term used to refer to the time before a fever sets in.

anterior

In veterinary terms, used to refer to the front of the body.

anterior chamber

Veterinary term used to indicate the space behind the cornea of the eye and in front of the iris; contains liquid.

anterior pituitary

Term used to refer to the front of the pituitary gland; can be found at the bottom of the brain and is responsible for the secretion of certain hormones that deal with growth and other bodily functions.

anterior presentation

Refers to the normal position of an animal during birth, with the feet and head set to come out first.

anthelmintic

Usually used in veterinary medicine to refer to certain drugs that are designed to combat intestinal worms in animals.

antiarrhythmic

Used to refer to any drug that alters irregularities in an animal's heartbeat.

antibacterial

Used to refer to any drug or medical substance that has the ability to slow down or stop the growth of bacteria and other such organisms.

antibiosis

A relationship between two organisms in which one of the organisms causes harm to or kills the other.

antibiotic

Term used to refer to any substance that is used to slow down the growth of bacteria or stop it altogether.

antibody

A protein in the body that is designed to fight disease; antibodies are brought on by the presence of certain antigens in the system.

anticarcinogen

Refers to any substance that slows down or stops the activities of any substance known to be a carcinogen (known to cause cancer).

anticoagulant

Term used to refer to any drug that is used to slow down or stop the clotting of blood for medical purposes.

anticonvulsant

Term used to refer to any substance or drug that stops seizures.

antidiarrheal

Term used to refer to any drug or substance that is known to prevent bowel movements or stop diarrhea.

antidiuresis

A condition in which urine is produced and eliminated on a slower basis.

antidote

Any substance used to combat the effects of certain poisons.

antiemetic

Term used to refer to any drug or substance that is used to control vomiting.

antigen

Any substance or item that the body of an animal would regard as strange or unwanted; a foreign disease or virus in the body (toxin, etc.)

antihypertensive

Term used to refer to any drug that lowers an animal's blood pressure.

antimutagen

Term used to refer to any substance that slows down or prevents the activity of a mutagen.

antineoplastic agent

Term used to refer to a drug that is used to treat a neoplasm.

antioxidant

Term used to describe certain feeds; refers to c or anything else that contains compounds that prevent the process of oxidization.

antipruritic agent

Any drug that is used to control itching and resultant inflammation.

antipyretic

Term used to describe a drug that is used to reduce a feverish temperature.

antisepsis

Preventing certain infections by destroying or excluding certain organisms that may be known to contribute to them.

antiseptic

Any drug that kills organisms in an animal's tissue or prevents the growth of more.

antiserum

Any serum that is known to contain the antibodies that contain the antigen necessary to combat a certain disease; usually contains antibodies extracted from an animal that has been infected with the disease and built up an immunity

antispasmodic

Any drug that is known to prevent spasms of any muscles in the body.

antitoxin

A type of antiserum that contains antibodies against certain poisons.

antitussive

A medication designed to reduce or eliminate a cough.

antivivisectionist

Any person who is against or works against surgery on live animals for the purpose of education or veterinary research.

antler

An object protruding from the skull on certain animals; deciduous and ossified in nature. May be found on deer, elk, etc.

antrum

The empty space inside any hollow organ or bodily structure.

anuria

The lack of production of urine in an animal's body.

anus

The end of the gastrointestinal tract; the opening at the end of the tract.

aorta

The name of the main artery that starts in the left ventricle of an animal's four chamber heart.

aortic semilunar valve

The fold of membranes between the left ventricle and the aorta.

apathy

Lack of caring; indifference.

aperture

Any type of opening

apex

The very tip or peak of something

aphakia

The absence of a lens, as in an eye.

aphtha

A small sac inside the udder, between the toes, or inside the mouth of certain animals; may have to do with a foot-and-mouth disease or affliction.

Apia matter

The third layer of the meninges

aplasia

When a certain organ or vital tissue fails to properly or fully develop.

apnea

Failure to breathe properly, as in while sleeping; lack of breathing.

appendage

Something that is attached to something else, usually something larger; e.g. a leg or an arm.

appendicular skeleton

The bones that make up the extremities on the body, including the shoulders, etc.

appositional

Placing something side-by-side with something else.

approach

In veterinary terms, the term used to refer to the procedure by which a certain part will be dissected and/or exposed.

apterium

Term used to refer to an area on a bird that lacks feathers.

apterous

Lacking wings.

aqueous humor

Term used to refer to the liquid that gives nourishment to the structures inside the rear segment of an animal's eye.

arachnid

A group of bugs known for having four pairs of legs and either one or two bodily segments; spiders are the most famous of all arachnids.

arachnoid

Term used to refer to something being constructed of tiny hairs; a cobweb is arachnoid in nature.

arch

A bend or curve

archetype

A biological term that refers to plants or animals from which certain qualities have been inherited.

arena

The place where something happens; the area in which certain actions take place.

ark

A term usually used in the context of care for rabbits; a little structure with a ridged roof that may be used to house rabbits.

arrector pilus

The muscle that is attached to the hair follicle that causes the hair to stand up straight; the plural form of this word is arrector pili.

arteriectomy

The removal of part of an artery by surgical procedure.

arterioles

The smaller veins or arteries that extend out from larger arteries.

arterioplasty

A surgical procedure in which damage to an artery is rectified or an artery is repaired.

arteriosclerosis

A medical condition in which arteries become thicker and harder in texture.

arteriotomy

A medical procedure in which an artery is cut or sliced open.

artery

A large blood vessel that transports blood out of the heart.

arthralgia

Term used to refer to a medical condition that causes pain in the joints.

arthritis

A medical condition in which the joints become inflamed and causes a great deal of pain.

arthrocentesis

A medical procedure in which the joints are punctured in order to remove fluid.

arthrodesis

A surgical procedure in which vertebrae in the spine or a joint is surgically fused.

arthrodynia

A term used to refer to pain in the joints

arthrogram

A recording of the examination of a joint after dye has been injected to detect contrasts for some medical purpose.

arthrography

The process of performing an examination on a joint after dye has been injected into the joint.

arthrology

The study of joints, joint pain, and anything related to the joints.

arthropathy

A disease affecting a joint in the body.

arthropod

An animal belonging to the phylum Arthropoda; characterized by an external skeleton and jointed legs. May include certain insects and crustaceans.

arthroscope

A medical instrument used to look at the inside of a joint.

arthroscopy

The endoscopic method of examining the inside of a joint.

arthroslecrosis

A medical condition by stiffening or hardening of the joints.

artificial hormone

A hormone that is created to be used in place of hormones that an animal's body would have produced naturally otherwise.

artificial insemination

A method of breeding in which semen is collected and stored to be inserted into the vagina without actual breeding activity; often shortened to AI in the veterinary world.

artificially acquired immunity

Term used to refer to immunity that comes about because a vaccine was administered.

artiodactyla

A zoological term used to refer to a certain order of mammals; includes animals with hooves and an even number of toes.

ascending

Moving upward

ascites

The collection of fluid in the peritoneal cavity.

ascorbic acid

Vitamin C; C6F1806; known to prevent scurvy and is found in fruits and vegetables.

asepsis

A medical state in which infection is not present

aseptic technique

Term used to refer to cautions used in order to prevent a wound from becoming infected or contaminated.

asper

Term used to indicate raspy or rough.

asphyxia

A medical condition resulting in a lack of oxygen, usually resulting in death.

asphyxiation

A lack of breathing due to a purposeful cut off of air; may also be referred to as suffocation.

aspirate

a) inhaling b) getting out fluid or gas by the act of sucking.

assay

A type of test that is used to count the number of organisms in a particular sample.

assess

To make a decision about or evaluate.

assessment

A test or evaluation.

assimilation

The absorption of something

asthenia

Lack of strength in the body; weakness; inability to perform excessive amounts of work.

asthma

An allergic disorder that results in difficulty breathing.

astomous

Without a mouth

astringent

Any drug that is known to cause tissues to contract, such as tannic acid, zinc oxide, or zinc sulfate.

astrocyte

A type of shell that is shaped like a star

astrocytoma

A tumor of the head that is made up of astrocyte (star-shaped) cells.

asymmetrical

Out of proportion or unbalanced; may also be referred to as unsymmetrical.

asymptomatic

Term used to refer to a condition of having a disease or affliction but not displaying symptoms of it.

asystole

A term that indicates a lack of contraction; used to refer to a lack of activity in the heart.

atavism

The re-emergence of a disease or a certain characteristic after it has skipped one or more generations.

ataxia

A medical condition in which an animal is unable to control the movements of their muscles; may result in collapse or stumbling.

atelactasis

A medical condition in which the alveoli fail to fully expand or collapse due to a lack of air.

atherosclerosis

A medical condition in which the arteries become small and hard as the result of excessive fatty deposits.

atlas

The number one cervical vertebrae.

atomization

The process in which a liquid is turned into a very fine spray.

atonic

Lacking control of the muscles.

atopy

A form of hypersensitivity or allergy in certain animals.

atraumatic

Term used to refer to something that results from a method of treatment that caused no trauma or damage.

atresia

The absence of a body opening that would normally be there; the absence of a certain organ that is tubular in structure.

atrioventricular

The atrium and the ventricle.

atrioventricular node

A mass of tissue that can be found inside the right atrium; transmits electrical impulses to certain areas of the heart.

atrioventricular valve

The fold of membranes found among the front and rear chambers of the heart; may be described as the left and right atrioventricular valve.

atrium

The superior chamber in an animal's heart.

atrophy

The wasting away of certain tissues; a medical condition that occurs when tissues fail to grow.

attaint

A wound that can be found on the leg of a horse; an attaint can be attributed to damage caused by a horse's own hooves.

attenuate

To wear down or reduce; to dilute or make thinner.

attenuation

The term used to refer to the decrease in intensity of an ultrasound beam as it travels through bodily tissue.

atypical

Deviating from the normal; not typical.

aubin

A term used to describe a strange gait in a horse; it is slower than normal but may resemble a gallop.

auditory

Anything pertaining to what can be heard; hearing.

auditory ossifies

Term used to refer to a group of three small bones in the heart that transmit certain vibrations and allow for hearing.

aural

Referring to the ear.

aural hematoma

A pooling or mass filled with blood that can be found in the outer ear.

auscultation

The use of a stethoscope (usually) in listening to the sounds of an animal's body.

autoclave

A device used to sterilize instruments with the use of pressurized steam.

autogenous vaccine

A vaccine that is made from the bacteria of the patient it is being used to treat.

autoimmune disease

Any disease in which an animal's body creates antibodies that are used against itself.

autoimmunity

A medical condition in which an animal becomes allergic to its own tissues; may result in a severe illness.

autolysis

The process in which meat ‘rots' after slaughtering or fruits or vegetables become soft; also referred to as self-digestion.

autonomic nervous system

The part of the nervous system that contains the nerves that control involuntary movement.

autosome

A chromosome not involved in determining sex.

autotrophic

A term used to indicate an organism that creates their own source of food.

autumn lag

Term used to refer to the period of autumn in which certain animals cease reproduction.

available energy

Term used to refer to energy that can be metabolized.

average daily gain (adg)

The process of calculating an animal's weight after weaning by dividing the number of pounds gained by the number of days they have been on actual feed.

avian

Term used to indicate something that involves birds.

aviary

A place where birds are kept.

avicide

Any substance that is used to kill birds.

aviculture

The study of caring for birds; the act of raising birds.

avirulent

A term used to indicate that something lacks the ability to create a disease.

avitaminosis

A disease that occurs as the result of a deficiency of a certain type of vitamin.

avoidance

A condition in which certain organisms can purposely prolong the amount of time they are dormant as the result of some type of environmental stress.

avulsion

The tearing or breaking away of a part.

axenic

A term used to indicate that something is free of germs.

axial feather

The feather in the middle of a bird's wing that is used to separate the primary feathers and the secondary feathers.